1. Field of the Invention
This invention relates to a toner-replenishing apparatus usable in a dry process electrostatic copier and particularly relates to a toner supply device that supplies dry toner at a uniform rate. Even more particularly, it relates to a supply device of the type comprised of a toner tank having a discharge outlet in the bottom thereof and a toner-dispensing rotary brush disposed in the tank in sliding contact with said outlet. The tank holds a large quantity of toner and an appropriate amount of this toner is supplied to a conventional developing unit by operation of the brush through suitable drive means.
2. Discussion of the Prior Art
Dry toner contained in the supply tank of a toner-supplying device has inherent viscosity which can, under adverse conditions, cause lumps to form in the mass of toner, leading to cavities beneath the lumps in the toner mass as toner is dispensed. In other words, it can cause a bridging phenomenon to occur, thereby impairing performance of the toner-supplying function of the tank. To avoid such bridging, in the past there have been provided means (i.e., mechanism) for shaking the toner tank itself or an agitating device has been disposed inside the tank for mechanically stirring the toner mass. Each of these countermeasures against toner bridging requires a specific mechanism to drive the tank-moving means or the agitating device, hence any apparatus including such a mechanism becomes bulky and complicated in construction.